Underground Anchor Device and Retaining Wall Structure Using the Same

Abstract

The present invention relates to an underground anchor device and a retaining wall reinforcement structure using the same, which is embedded underground to secure the stability of a retaining wall reinforcement structure installed on a cut slope or embankment ground, and is based on a structure that is fixed by grouting inside the embedded hole using a corrugated steel pipe, and which can effectively prevent the anchor from being pulled out even after grouting curing. The underground anchor device according to the present invention comprises a corrugated steel pipe inserted into the interior of a buried hole formed in the ground, a fixing member fastened to one end of the corrugated steel pipe, a connecting member inserted into the interior of the corrugated steel pipe and fixed by the fixing member, with one end located inside the corrugated steel pipe and the other end connected to an external structure, and an expandable locking unit installed inside the corrugated steel pipe, which moves radially outward by the connecting member as the connecting member is inserted and protrudes to the outside of the corrugated steel pipe, thereby being fixed to a grouting material filled inside and outside the corrugated steel pipe to prevent the corrugated steel pipe from being pulled out.

Description

Technology Field

[0001] The present invention relates to an underground anchor device and a retaining wall reinforcement structure using the same, and more specifically, to an underground anchor device and a retaining wall reinforcement structure using the same that is buried underground to secure the stability of a retaining wall reinforcement structure installed on a cut slope or an embankment ground, and is based on a structure that is fixed by grouting inside the buried hole using a corrugated steel pipe, and is capable of effectively preventing the anchor from being pulled out even after grouting curing. Background Technology

[0002] In general, various types of retaining wall structures are constructed in civil engineering projects such as road construction, residential land development, river maintenance, and embankment construction to prevent the collapse of cut slopes or fill ground and to ensure structural stability. Since these retaining wall structures are continuously exposed to various external forces such as earth pressure, water pressure, and seismic loads, the performance of the underground anchors supporting them, as well as the stiffness of the structure itself, has a very important impact on the overall structural stability.

[0003] In particular, for retaining wall structures installed on cut slopes, a method is widely used in which holes are drilled at regular intervals in the cut slope, anchors are inserted into them, and grouting material is injected to fix the anchors to the ground. These anchors are connected to blocks or precast panels installed on the front of the retaining wall and serve to transmit the overturning moment and earth pressure acting on the retaining wall to the ground.

[0004] Conventionally, rod-shaped members such as reinforcing bars were primarily used as underground anchors. In this case, construction was carried out by inserting the reinforcing bar into the burial hole, injecting grouting material, and then connecting it to a retaining wall structure using the exposed portion of the reinforcing bar after the grouting had cured. However, these reinforcing bar-based anchors have a relatively small surface area, which limits their adhesion to the grouting, and they suffer from insufficient resistance to pull-out under long-term load application. Additionally, since reinforcing bars are not structurally hollow, the grouting material does not flow into the interior, which limits the formation of internal bonding strength.

[0005] To address these issues, underground anchor structures utilizing corrugated steel pipes with spiral sections on their outer surfaces have recently been proposed. Corrugated steel pipes have a large surface area and an uneven outer surface structure that increases the contact area with grouting, thereby improving adhesion strength. Furthermore, because the interior is hollow, grouting material can be filled both inside and outside, creating a more stable fixation state. Additionally, corrugated steel pipes are relatively lightweight, offering the advantages of improved constructability and ease of transportation.

[0006] However, since these corrugated steel pipe-based anchor structures also rely fundamentally on the adhesion and curing strength of the grouting material for fixation to the ground, there is a possibility that their long-term pull-out resistance may decrease in environments with poor ground conditions or conditions involving repetitive loading, vibration, or groundwater flow. In particular, if minute loosening or cracking occurs at the interface between the grouting layer and the ground, the entire anchor may be slowly pulled out, which can lead to a decrease in the stability of the retaining wall structure.

[0007] In addition, since a separate mechanical locking structure is not formed after the anchor is embedded in the existing structure, there is a limitation in that pull-out resistance must be secured solely by the grouting strength, and as a result, there are problems such as requiring excessive design margins or increasing construction costs under high load conditions. Prior art literature

[0008] Korean Registered Patent Publication No. 10-1488721: Method for expanding the bulb of an underground anchor pile and a bulb expansion device used in the said method Korean Registered Patent Publication No. 10-1420763: Underground anchor and ground reinforcement structure using the same The problem to be solved

[0009] The present invention was created to solve the above problems, and aims to provide an underground anchor device and a retaining wall reinforcement structure using the same, which can effectively prevent the anchor from being pulled out by forming a mechanical locking structure with the ground even after grouting curing by providing an expandable locking unit installed inside a corrugated steel pipe that expands outward according to the insertion of a connecting member. means of solving the problem

[0010] The underground anchor device according to the present invention comprises a corrugated steel pipe inserted into the interior of a buried hole formed in the ground, a fixing member fastened to one end of the corrugated steel pipe, a connecting member inserted into the interior of the corrugated steel pipe and fixed by the fixing member, with one end located inside the corrugated steel pipe and the other end connected to an external structure, and an expandable locking unit installed inside the corrugated steel pipe, which moves radially outward by the connecting member as the connecting member is inserted and protrudes to the outside of the corrugated steel pipe, thereby being fixed to a grouting material filled inside and outside the corrugated steel pipe to prevent the corrugated steel pipe from being pulled out.

[0011] The corrugated steel pipe has a plurality of protruding holes formed at points corresponding to the installation location of the expandable locking unit, penetrating the inner and outer surfaces, and the expandable locking unit comprises a ring support member having an outer ring support member installed to contact the inner surface of the corrugated steel pipe and an inner ring support member formed to have an outer diameter smaller than that of the outer ring support member and arranged to be spaced apart from the outer ring support member by a predetermined distance, and a plurality of expandable locking members formed to penetrate the inner ring support member and the outer ring support member and extend along the radial direction of the corrugated steel pipe, and spaced apart from each other by a predetermined distance along the circumferential direction of the inner ring support member and the outer ring support member, wherein one end of the expandable locking member is located on the inner side of the inner ring support member and is pressed by the connecting member that passes through the center of the inner ring support member and enters the interior of the corrugated steel pipe, thereby moving toward the exterior of the corrugated steel pipe along the radial direction to the exterior of the corrugated steel pipe It is desirable to form it so that it protrudes.

[0012] Preferably, the above-described expandable locking unit comprises a plurality of ring support members spaced apart from each other at a predetermined interval along the longitudinal direction of the corrugated steel pipe, each ring support member being interconnected by a ring connector connecting the outer ring support members, and the expandable locking member comprises a head portion disposed inside the hollow of the inner ring support member and formed to be radially movable by the connecting member upon entry of the connecting member, an extension rod extending from the head portion through the inner ring support member and the outer ring support member, and a protrusion formed at the end of the extension rod and exposed to the outside of the corrugated steel pipe through a protruding hole of the corrugated steel pipe when the head portion moves outward by the connecting member.

[0013] The head portion is formed with a curved contact surface so that it can be moved by the connecting member when the connecting member enters, and the protrusion is formed of a material capable of elastic deformation, and when the connecting member does not enter the inner ring support member and the expansion catch member is located inside the corrugated steel pipe, the protrusion is in a rolled state so that it is maintained at an outer diameter that can pass through the protrusion hole, and a strap-shaped binding member is formed to wrap around the outer surface of the protrusion to maintain the rolled state of the protrusion, and it is preferable that the protrusion is formed so that it becomes unfolded by elastic force as the binding member that cannot pass through the protrusion hole releases the binding of the protrusion during the process in which the protrusion passes through the protrusion hole due to the entry of the connecting member.

[0014] It is preferable that the inner ring support member has a head insertion groove formed on its inner surface so that the head portion can be inserted when the connecting member enters.

[0015] A retaining wall reinforcement structure using an underground anchor device according to the present invention comprises the underground anchor device, a grouting layer formed on the inside and outside of the corrugated steel pipe by being injected into the buried hole, and a structure in which the outer end of the connecting member is connected. Effects of the invention

[0016] According to the underground anchor device of the present invention and the retaining wall reinforcement structure using the same, a mechanical locking structure by an expandable locking unit is simultaneously formed along with the bonding force by the grouting layer, thereby having the effect of significantly improving the pull-out resistance of the anchor.

[0017] In addition, since the expansion structure is automatically formed during the insertion process of the connecting member without any additional separate processes, it offers excellent constructability and has the advantage of enabling the realization of a stable retaining wall reinforcement structure even under various ground conditions. Brief explanation of the drawing

[0018] FIG. 1 is a side cross-sectional view of a retaining wall reinforcement structure using an underground anchor device according to the present invention. FIG. 2 is an exploded perspective view of an underground anchor device according to the present invention. FIG. 3 is a perspective view of an extended locking unit extracted from the underground anchor device of FIG. 2. FIG. 4 is a front view showing the operating state of the extended locking unit of FIG. 3, FIG. 5 is a partial excerpt perspective view illustrating the protrusion of the granite-type locking unit of FIG. 3 in a rolled state and in an unfolded state. Specific details for implementing the invention

[0019] Hereinafter, an underground anchor device according to an embodiment of the present invention and a retaining wall reinforcement structure using the same will be described in detail with reference to the attached drawings. As the present invention is susceptible to various modifications and may take various forms, specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to the specific disclosed forms, and it should be understood that it includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the present invention. Similar reference numerals have been used for similar components in the description of each drawing. In the attached drawings, the dimensions of the structures are shown enlarged compared to the actual dimensions for the clarity of the present invention.

[0020] Terms such as "first," "second," etc., may be used to describe various components, but said components should not be limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component.

[0021] The terms used in this application are used merely to describe specific embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, terms such as "comprising" or "having" are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0022] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0024] FIG. 1 shows a retaining wall reinforcement structure (1) using an underground anchor device according to the present invention, and FIG. 2 to 5 show an embodiment of an underground anchor device (10) according to the present invention.

[0025] An underground anchor device (10) according to one embodiment of the present invention is installed in a buried hole (20) formed in the ground to secure the stability of a retaining wall reinforcement structure, and comprises a corrugated steel pipe (100), a fixing member (200) fastened to one end of the corrugated steel pipe (100), a connecting member (300) inserted into the interior of the corrugated steel pipe (100) and fixed by the fixing member (200), and an expandable locking unit (400) installed inside the corrugated steel pipe (100).

[0026] The corrugated steel pipe (100) is formed as a hollow tube that is inserted into the burial hole (20), and a spiral-shaped protrusion is formed on its outer surface. This structure is intended to increase the contact area with the grouting material to improve adhesion within the burial hole (20). Additionally, although not illustrated, a plurality of grouting flow holes that communicate the inside and outside may be formed in the corrugated steel pipe (100) as needed, and through this, the grouting material can be evenly filled into the inside and outside of the corrugated steel pipe (100) to simultaneously form an inner grouting layer and an outer grouting layer.

[0027] The above fixing member (200) is fastened to one end of the corrugated steel pipe (100) to fix the connecting member (300), and includes a first fastening part (210) that is fastened to a spiral portion formed on the outer surface of the corrugated steel pipe (100), and a second fastening part (220) that presses and fixes the connecting member (300).

[0028] The first fastening part (210) has a fastening hole formed with a spiral corresponding to the spiral shape of the corrugated steel pipe (100), and the corrugated steel pipe (100) can rotate and enter the interior of the first fastening part (210) to be fastened.

[0029] The second fastening part (220) may be formed as a clamp structure and configured to firmly fix the connecting member (300) by pressing from the outside through the fastening member (221) while the connecting member (300) is inserted.

[0030] In this embodiment, the second fastening part (220) is in the form of a clamp that wraps around the connecting member (300), but the second fastening part (220) can be implemented in various forms other than this embodiment so that it can be fixed while the connecting member (300) is inserted inside.

[0031] The above connecting member (300) is a member in which one end is located inside the corrugated steel pipe (100) and the other end is connected to an external structure (40) such as a precast panel or block, and performs the role of transmitting the load acting on the retaining wall into the ground.

[0032] The above connecting member (300) may be configured in the form of a reinforcing bar, a steel rod, or a cable, and tension may be applied while fixed by the fixing member (200). In this embodiment, the connecting member (300) serves as an operating part that moves the expansion catch member (430) of the expansion catch unit (400) described later in a radial direction. Therefore, it is preferable that the above connecting member (300) be formed as a rigid member, and it is preferable that one end entering the interior of the corrugated steel pipe (100) be formed in a shape in which the outer diameter gradually decreases as it progresses toward the end.

[0033] The above-mentioned expandable catch unit (400) is installed inside the corrugated steel pipe (100) and operates as the connecting member (300) is inserted into the corrugated steel pipe (100) to form a structure that protrudes to the outside of the corrugated steel pipe (100), thereby preventing the corrugated steel pipe (100) from being pulled out of the buried hole (20) after the grouting layer (30) is formed.

[0034] In the corrugated steel pipe (100), a plurality of protruding holes (110) are formed that penetrate the inner and outer surfaces at points corresponding to the installation location of the expandable locking unit (400). These protruding holes (110) serve as passages that allow a part of the expandable locking unit (400) to protrude outward.

[0035] The above-described expandable locking unit (400) is configured to include a ring support member (410) and a plurality of expandable locking members (430). The ring support member (410) consists of an outer ring support member (411) installed to contact the inner circumference of the corrugated steel pipe (100), and an inner ring support member (413) positioned at the center side having an outer diameter smaller than that of the outer ring support member (411). The inner ring support member (413) and the outer ring support member (411) are spaced apart at a predetermined interval, allowing the expandable locking member (430) to move in a radial direction through the space between them.

[0036] The outer ring support member (411) is formed such that its outer diameter corresponds to the inner diameter of the corrugated steel pipe (100), and the outer diameter of the inner ring support member (413) is formed to be smaller than the inner diameter of the outer ring support member (411), so that a predetermined space is formed between the inner surface of the outer ring support member (411) and the outer surface of the outer ring support member (411), and three spacers (417) are formed at equal intervals along the circumferential direction to maintain this gap.

[0037] Since the inner ring support member (413) is formed as a ring-shaped member whose inner diameter corresponds to the outer diameter of the connecting member (300), the connecting member (300) can enter along the interior of the corrugated steel pipe (100) through the central through hole (416) of the inner ring support member (413).

[0038] The above ring support members (410) are spaced apart along the longitudinal direction of the corrugated steel pipe (100). In this embodiment, three ring support members (410) are installed spaced apart along the longitudinal direction of the corrugated steel pipe (100), and each ring support member (410) is interconnected by a ring connector (420) to form an integrated structure. In this embodiment, two ring connectors (420) are formed to connect each ring support member (410), but three or more ring connectors (420) may support each ring support member (410) spaced apart along the circumferential direction.

[0039] The above-mentioned extension locking member (430) is installed at each ring support member (410), and is formed so that its end can protrude to the outside of the corrugated steel pipe (100) while moving in a radial direction from the ring support member (410).

[0040] To explain the structure of the extension locking member (430) more specifically, the extension locking member (430) includes a head portion (431) located on the inner side of the inner ring support member (413), an extension rod (432) extending outward from the head portion (431), and a protrusion (433) formed at the end of the extension rod (432).

[0041] It is preferable that the head portion (431) has a curved contact surface so that it can be moved toward the outer surface of the inner ring support member (413) by contacting the connecting member (300) when the connecting member (300) is inserted. Accordingly, when the connecting member (300) is inserted through the through hole (416) formed in the center of the inner ring support member (413), the outer surface of the connecting member (300) presses against the head portion (431), and thereby the expansion locking member (430) moves in a radial direction.

[0042] A second through hole (414) is formed in the inner ring support member (413) so that the extension rod (432) of the extension locking member (430) can pass through it, and the head portion (431) is formed to have a diameter relatively larger than the second through hole (414) so ​​that the head portion (431) cannot escape from the inner ring support member (413) and remains in a restrained state.

[0043] The above extension rod (432) passes through the inner ring support member (413) and the outer ring support member (411) and extends outwardly along the corrugated steel pipe (100), and serves to transmit the movement of the head portion (431) to the outside.

[0044] The above protrusion (433) is formed at the end of the extension rod (432) and is configured to be exposed to the outside through the first through hole (412) of the outer ring support member (411) and the protruding hole (110) of the corrugated steel pipe (100).

[0045] The above-mentioned protrusion (433) is formed of a material capable of elastic deformation and maintains a rolled state in an initial state so as to pass through the protrusion hole (110). To this end, a strap-shaped binding member (434) is formed to wrap around the outer surface of the protrusion (433) so as to maintain the rolled state so that the protrusion (433) can pass through the first through hole (412).

[0046] Subsequently, when the connecting member (300) is inserted and pressurizes the head portion (431), the entire expansion locking member (430) moves outward, causing the protrusion (433) to pass through the first through hole (412) and the protruding hole (110). During this process, the binding member (434) fails to pass through the first through hole (412) and detaches or breaks from the protrusion (433), thereby releasing the binding to the protrusion (433).

[0047] Accordingly, the protrusion (433) spreads out from the outside of the corrugated steel pipe (100) by its own elastic force, and the protrusion (433) spread out in this way is embedded in the grouting material filled inside the buried hole (20) to form a mechanical locking structure. Therefore, after the grouting material is cured, not only is there a simple adhesion force, but a physical locking effect caused by the protrusion (433) is added, effectively preventing the corrugated steel pipe (100) from being pulled out.

[0048] Additionally, a head insertion groove (415) may be formed on the inner surface of the inner ring support member (413) so that the head portion (431) can be partially inserted. This head insertion groove (415) facilitates the smooth movement of the head portion (431) when the connecting member (300) is inserted, and enables the operation of the expansion locking member (430) to be performed more stably.

[0049] Meanwhile, as illustrated in FIG. 1, a retaining wall reinforcement structure (1) using an underground anchor device according to the present invention comprises the underground anchor device (10), a grouting layer (30) formed on the inside and outside of a corrugated steel pipe (100) by being injected into the buried hole (20), and a precast panel or block-shaped structure (40) to which the outer end of a connecting member (300) is connected.

[0050] During construction, a buried hole (20) is first drilled in the cut slope, and then a corrugated steel pipe (100) is inserted into the buried hole (20). Afterward, a grouting material is injected to form a grouting layer (30) on the inside and outside of the corrugated steel pipe (100), and a fixing member (200) is fastened to one end of the corrugated steel pipe (100). Next, a connecting member (300) is inserted into the corrugated steel pipe (100) and fixed by the fixing member (200). During this process, an expandable locking unit (400) is operated so that a protrusion (433) protrudes outside the corrugated steel pipe (100). Afterward, as the grouting material cures, the expandable locking member (430) becomes integrated with the grouting layer (30) to form a strong pull-out resistance structure.

[0051] As such, according to the present invention, the adhesion force from grouting and the mechanical locking structure by the expandable locking unit (400) work together to secure significantly improved pull-out resistance performance compared to the prior art, and a stable retaining wall reinforcement structure can be realized even under various ground conditions.

[0053] The description of the presented embodiments is provided so that any person skilled in the art may use or practice the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the scope of the present invention. Thus, the present invention is not limited to the embodiments presented herein, but should be interpreted in the broadest possible scope consistent with the principles and novel features presented herein. Explanation of the symbols

[0054] 1: Retaining wall reinforcement structure 10: Underground anchor device 100: Corrugated steel pipe 110: Protruding hole 200 fixed member 210: 1st fastening part 220: 2nd fastening part 221: Fastening member 300: Connecting member 400: Expandable catch unit 410: Ring support part 411: Outer ring support member 412: First through hole 413: Inner ring support member 414: Second through hole 415: Head insertion groove 416: Through ball 417: Spacer 420: Ring connector 430: Extension locking member 431: Head section 432: Extension rod 433: Protrusion 434: Binding member 20: Burial hole 30: Grouting layer 40: Structures

Claims

Claim 1 A corrugated steel pipe inserted into the interior of a buried hole formed in the ground; a fixing member fastened to one end of the corrugated steel pipe; and a connecting member inserted into the interior of the corrugated steel pipe and fixed by the fixing member, with one end located inside the corrugated steel pipe and the other end connected to an external structure. and an expandable locking unit installed inside the corrugated steel pipe, which, as the connecting member is inserted, moves radially outward by the connecting member and protrudes to the outside of the corrugated steel pipe, thereby being fixed to the grouting material filled inside and outside the corrugated steel pipe to prevent the corrugated steel pipe from being pulled out; wherein the corrugated steel pipe has a plurality of protruding holes formed at points corresponding to the installation location of the expandable locking unit, penetrating the inner and outer surfaces, and the expandable locking unit has a ring support member having an outer ring support member installed to contact the inner surface of the corrugated steel pipe and an inner ring support member formed to have an outer diameter smaller than that of the outer ring support member and arranged to be spaced apart from the outer ring support member by a predetermined distance, and a plurality of rings extending along the radial direction of the corrugated steel pipe through the inner ring support member and the outer ring support member, and formed to be spaced apart from each other by a predetermined distance along the circumferential direction of the inner ring support member and the outer ring support member. An underground anchor device characterized by including an expansion catch member, wherein one end of the expansion catch member is located on the inner side of the inner ring support member, and is formed to protrude to the outside of the corrugated steel pipe by being pressed by the connecting member that passes through the center of the inner ring support member and enters the interior of the corrugated steel pipe, thereby moving toward the outside of the corrugated steel pipe along a radial direction. Claim 2 delete Claim 3 The underground anchor device according to claim 1, wherein the expandable locking unit is formed such that a plurality of ring support members are spaced apart from each other at a predetermined interval along the longitudinal direction of the corrugated steel pipe, and each ring support member is interconnected by a ring connector connecting the outer ring support members, and the expandable locking member comprises a head portion disposed inside the hollow of the inner ring support member and formed to be radially movable by the connecting member when the connecting member enters, an extension rod extending from the head portion through the inner ring support member and the outer ring support member, and a protrusion formed at the end of the extension rod and exposed to the outside of the corrugated steel pipe through a protruding hole of the corrugated steel pipe when the head portion moves outward by the connecting member. Claim 4 An underground anchor device according to claim 3, wherein the head portion has a contact surface formed as a curved surface so as to be movable by the connecting member when the connecting member enters, and the protrusion is formed of a material capable of elastic deformation, wherein when the connecting member does not enter the inner ring support member and the expansion locking member is located inside the corrugated steel pipe, the protrusion is in a rolled state so as to be maintained at an outer diameter that can pass through the protrusion hole, and a strap-shaped binding member is formed to wrap around the outer surface of the protrusion to maintain the rolled state of the protrusion, and wherein, as the protrusion passes through the protrusion hole due to the entry of the connecting member, the binding member that cannot pass through the protrusion hole releases the binding of the protrusion, thereby causing the protrusion to be formed in an unfolded state by elastic force. Claim 5 An underground anchor device according to claim 4, characterized in that the inner ring support member has a head insertion groove formed on its inner surface so that the head portion can be inserted when the connecting member enters. Claim 6 A retaining wall reinforcement structure using an underground anchor device, characterized by comprising an underground anchor device according to any one of claims 1, 3 to 5, a grouting layer formed on the inside and outside of the corrugated steel pipe by being injected into the buried hole, and a structure to which the outer end of the connecting member is connected.

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